Since 1975, sea turtles have been protected by the Washington Convention on Species Protection (Cites). Excessive fishing and industrial exploitation (from the turtle soup to the tortoiseshell) of the animals weighing up to 200 kilograms had severely decimated many species: it was feared that they would die out. Residents of secluded islands in the Pacific still regard turtles as a delicacy, despite the prohibition, they secretly capture and consume them.
However, this can lead to life-threatening health problems. A poison (chelonitoxin) contained in the flesh of the animals first leads to an unpleasant sensation in the mouth and throat area, then nausea and vomiting occur, followed by perspiration, dizziness and chest pain. After a few days, neurological symptoms occur and life-threatening organs such as the kidneys can cease their activity: the patient is threatened with a fatal multi-organ failure.
Four dead to Dorffest
At the end of 2010, on the island of Murilo in the Micronesian state of Chuuk, there was a massive chellonitoxin poisoning after the consumption of a real carpet turtle (Caretta caretta) on a Dorffest. A total of 90 people fell ill, of whom four - all of them children - died. The authorities of the island state suspect that poisoning after the consumption of turtle meat is not a rarity, but the ill people do not report, because they know that the catch of the animals is illegal.
However, Chelonitoxin poisoning appears to be the exception, since turtles have been eating for centuries and were a vital supply for the crew of sailing ships. Presumably it comes only under special circumstances to a Chelonitoxin poisoning. Marine biologists assume that accumulation of chelonitoxin occurs whenever the turtles have eaten micro-organisms that contain a precursor of the poison.
Suspected of being cyanobacteria of the species Lyngbya majuscula, which in turn synthesize a highly toxic substance, the Lyngbyatoxin. These bacteria grow on sea grass and underwater rocks, substrates that are dug by sea turtles. The thesis is that chellonitoxin is a Lyngbyatoxin converted by the metabolism of the turtle. The concentration of the poison in the cyanobacteria could depend on environmental factors such as water temperature and solar radiation and has increased because of the warming of the oceans.
Sea turtles would then become a health hazard if they absorb a particularly large number of cyanobacteria or the bacterial species has produced a great deal of Lyngbyatoxin due to altered environmental factors.
For the endangered sea turtles, the mass poisoning in Micronesia is perhaps a survival advantage. The deadly poisoning epidemic has spread around the islands of the Pacific Ocean and may result in more than prohibitions.